Prune grader



Nov. 27, 1928. 1,693,042

. P. MOTHORN PRUNE GRADER Filed March 12. 1928 W. l Il hllflli n m. H- 1n- O .13 a" f 11 W INVENTOR.

Patented Nov. 27, 1928.

UNITED STATES PRESSLEY MOTHORN, OF HEALDSBURG, CALIFORNIA.

PRUNE GRADER.

Application filed March 12, 1928.

I The present invention relates to a gradmg table and more particularly to that type of table employing the well known shaking or grading screen on which the commodity to be graded is deposited and due to a vibratory motion is freed from foreign substance, and is separated into several sizes or grades, they being respectively deposited in bins or storage apparatus.

The principal object of this invention is to provide an apparatus of the above type wherein the sorting bins are stationary at all times, thus relieving the agitation on the material deposited therein, and removing the weight of the solid material within the bins from the shaking table or screen, enabling the use of less power in the sorting and grading, and enabling the discharge of the sorted or graded material from the bins into trays or other apparatus.

The present invention is particularly designed for handling prunes, and consists primarily of three inter-related screening elements carried by a vibrating frame, onto one of'which the prunes, as picked from the ground, are deposited, with their attendant foreign material, and by the agitation of the screen mounting frame are advanced over the screen and separated from the foreign material, and are delivered onto a coarser screen for grading; the larger sizes being retained on the screen and conveyed by agitation therefrom to a sorting bin; the smaller sizes passing through the screen and being separated, one falling through the screen immediately below into a bin and the size retained on the screen being conveyed by the movement of the shaking table to a suitable sorting bin.

With the above mentioned and other objects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings and pointed out in the claims hereto appended; it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings Figure 1 is a view in top plan of one embodiment of my invention.

Figure 2 is a view in side elevation.

Figure 3 is a view from the discharge end of the apparatus.

Serial No. 260,864

Figure 4 is a horizontal sectional view on line 4-4: of Fig. 1.

In the drawings, 1 indicates an open supporting frame substantially rectangular in plan, and at one end provided with a table portion 2, horizontally disposed within the open portion of the frame 1, and supported on links 3 is the frame 4, of a conventional shaking table. The frame 4 has imparted thereto a vibratory movement by actuating cams 5 movement of which is conveyed to the frame 4; by operating links 6.

Disposed transversely of the frame 4, at its receiving end, is a body of screen material 7 of relatively-fine mesh. Midway of the length of. frame 1 is disposed at second body of mesh material 8, of considerably larger mesh than that of 7, the two being on the same horizontal plane, and immediately below the body 8 is a third body of mesh material 9, the same being of considerably smaller mesh than that of 8.

Prunes deposited on the screen 7 will be, by the vibratory movement thereof, be agitated and conveyed therefrom onto the screen 8. In their movement, the chaff or foreign material will be separated therefrom and fall through screen 7.

The prunes of a size larger than the mesh of the screen 8 will be supported thereby and in turn conveyed by the vibratory movement thereof to its discharge end, while the prunes passing through the screen 8 will deposit on the screen 9, and those of sufficient size to be supported by the screen 9, will, by its vibratory movement, be conveyed to its discharge end, the smaller prunes passing through the screen 9'into bin 10. Bin 10 generally receives the smaller sizes or culls.

As the prunes are discharged respectively from the discharge ends of screens 8 and 9, they pass onto conveying surfaces 11 and 12, disposed transversely of the frame 4, in superimposed horizontal planes, the prunes on the conveying surface 11 directed toward one oblique dis-charge end of the shaking table by the outstanding wall 13 and discharged from the surface 11 into a bin 1 1- disposed parallel with the oblique edge 15 of the frame 4, but in a plane below the same, as in Fig. 2, resting on the table 2.

The prunes discharged onto the surface 12 are directed by the wall 16 to the oblique discharge end 17 at the opposite side of frame 4 from edge 15, and the prunes as they discharge from the oblique wall 17 deposit in a bin 18 supported on the table 2, with its upper edge in a plane below that of the discharge surface 12.

The respective bins l t and 18 are provided with manually controlled outlets 19, in the form of hinged doors, to admit of the contents of the bins being deposited on a tray, conventionally illustrated at 20, and which also rests on the table 2.

It will be observed that by the agitation of the table 4'. the prunes deposited thereon are cleaned and graded, and are deposited from the other end thereof into bins, which are supported independently of the frame, and which are held stationary in such position that the weight of the prunes therein is not placed on the vibratory frame.

While the prunes are received at different horizontal elevations on the surfaces 11 and 12, it will be observed. that they discharge from the oblique edges 15 and 17 in the same horizontal plane. This is accomplished by making a step at the point 16 in the upper surface 11.

The formation of the discharge points for the graded. fruit at opposite sides of thedischarge end of the shaking table enables the positioning of the receiving bins in a stationary manner and. affords a discharge area of considerable length for each surface.

The oblique arrangement of the discharge edges'enables a. long narrow bin to be provided for receiving fruit from each edge. This structure affords better distribution of the fruit on the long side of the tray and: overcomes the necessity of manually spreading the fruit in the bin when a short bin is provided, which is necessary by the present structures.

It will be observed that the bins discharge length-wise onto the trays from either side edges. This arrangement reduces to aminimum the mechanical spreading action required to distribute the fruit over the tray surface.

I claim A prune grader comprising a shaking table provided at one end with a. plurality of shaking screens disposed in superimposed horizontal planes, said table side Walls at its op posite end being obliquely disposed and converging to a point, means for imparting a longitudinal vibratory movement to therial received on said surfaces from said screens longltudinally o-f'the surfaces toward their respective oblique edges, with the prunesdischarging from the oblique edges in thesame horizontal plane at opposite sides of the shal'ring table, and fixed bins beneath the surface discharge ends for receiving the material therefrom.

In testimony whereof I have signed my name to this specification.

PRESSLEY MOTHORN. 

